What it says on the tin: the newest Pixelmon release for 1.16.5, Pixemon 9.1.12, breaks JEI, Specifically, you can no longer click to move crafting ingredients into the crafting grid to make crafting easier.

This is an absolutely massive quality of life issue. Having to manually place ingredients into the crafting grid, especially for these big mods, is a tedious waste of time and extremely irritating to players.

However, remember that if you downgrade, the previous version of Pixelmon, 9.1.11, breaks catching outside of battle, so you must go all the way back to 9.1.10 to get rid of both bugs. Staying out-of-date is also a problem.

I noted someone said to use a JEI alternative, REI, which apparently is compatible with JEI plugins. I will have a look at what REI is capable of, especially because it is important that it still show Pixelmon drops.